1. Field of the Invention
The present invention relates to a display device, and more particularly, to a flat panel display device, and a picture quality controlling method thereof, that improves picture quality by electrically compensating for panel defects.
2. Discussion of the Related Art
Recently, there has been an increase in development of various flat panel display devices with decreased weight and size, both of which are disadvantages in cathode ray tube display devices. The flat panel display devices include liquid crystal display devices, field emission display devices, plasma display panels, organic light emitting diode devices, and the like.
Generally, the flat panel display devices include a display panel for displaying a picture. During testing, panel defects, or mura defects, has been found in such display panels. For instance, the discovered panel defects include defects such as a display spot accompanying difference in brightness on a display screen. The panel defects are mostly generated during a fabricating process. Some of the defects may have a fixed shape, such as dot, line, belt, circle, polygon, or the like. Other defects may have an unspecified shape.
Examples of various panel defects are shown in FIGS. 1 to 3. FIG. 1 shows a panel defect of unspecified shape, FIG. 2 shows a panel defect having a vertical bar shape, and FIG. 3 shows a panel defect having a dot shape. The panel defect having vertical stripes is mainly caused by overlapping exposure, a difference in the number of lenses, and the like. The panel defect having dots is mainly caused by impurities. Images displayed in the location of such defects appear darker or brighter than an ambient non-defect area. Color difference is also perceivable when compared with the non-defect area.
The panel defects may degrade the final product to a certain degree, lowering product yield, and ultimately leading to increased cost. Further, even if the product with the panel defect is shipped as a good product, the deteriorated picture quality due to the panel defect reduces product reliability.
Accordingly, various methods have been proposed to reduce the panel defect. However, methods of the related art to reduce the problem are mainly directed to solving problems in the fabrication process. Disadvantages of such methods include difficulties in properly dealing with the panel defects generated in the improved process.